ESA ESOC: Giotto mission retrospective

A retrospective of ESA's historic Giotto mission with highlights of past comet science and featuring Rosetta and its ambitious goal to land on a comet in 2014.

NASA Stardust: Comet chaser going off-line

NASA's comet trekking spacecraft Stardust has officially ended operations. Stardust sent its last transmission to Earth on March 24 having traveled an incredible 3.54 billion miles (5.69 billion kilometers) over a 12 year period to become "NASA's most traveled comet hunter."

NASA's overview of the Stardust project can be seen in the video below:

"This is the end of the spacecraft's operations, but really just the beginnings of what this spacecraft's accomplishments will give to planetary science," said Lindley Johnson, Stardust-NExT and Discovery program executive at NASA Headquarters in Washington. "The treasure-trove of science data and engineering information collected and returned by Stardust is invaluable for planning future deep space planetary missions."

Launched on Febuary 7, 1999, Stardust's prime mission was to travel past an asteroid named Annefrank and onwards to Jupiter to collect particle samples from the comet Wild 2.

The mission was successfully completed in 2006 after the spacecraft traveled back to Earth to deliver its particle sample canister.

With Stardust in great condition and with plenty of fuel onboard, NASA gave the spacecraft a new name, Stardust NExT, and a new directive to take images of the comet Tempel 1 which was struck by a probe during the Deep Impact mission in 2005. This marked the first time a comet has been visited twice, and the first spacecraft to visit two comets.

Stardust's last undertaking was to burn the remaining fuel in its tanks and fuel lines.

As there are no reliable fuel gauges in the weightless environment of space, mission planners use fuel consumption models to track fuel levels by calculating the vehicle's flight history with the amount and length of time rockets have fired.

"Stardust's motors burned for 146 seconds," said Allan Cheuvront, Lockheed Martin Space Systems Company program manager for Stardust-NExT in Denver. "We'll crunch the numbers and see how close the reality matches up with our projections. That will be a great data set to have in our back pocket when we plan for future missions."

Stardust successfully completed all missions in its long life and is a model of durability and reliability for its builders Lockheed Martin Space Systems.

"This kind of feels like the end of one of those old western movies where you watch the hero ride his horse towards the distant setting sun -- and then the credits begin to roll," said Stardust-NExT project manager Tim Larson from NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Only there's no setting sun in space."

NASA JPL - Comet Tempel-1 Image Gallery

This image obtained by NASA's Stardust spacecraft shows a side of the nucleus of comet Tempel 1 that has never been seen before.

In the image, three terraces of different elevations are visible, with dark, banded scarps, or slopes, separating them.

The widest of the banded slopes is about 2 kilometers (1 mile). The lowest terrace has two circular features that are about 150 meters (500 feet) in diameter.


This image was taken on February 14, 2011, at 8:39:21 p.m. PST. The spatial resolution is about 15 meters (50 feet) per pixel.

NASA's Deep Impact spacecraft visited this same comet in July 2005 and also observed the presence of layers on the other side of the comet.

This image shows at least 90 percent new territory.

Stardust-NExT is a low-cost mission that will expand the investigation of comet Tempel 1 initiated by NASA's Deep Impact spacecraft. JPL, a division of the California Institute of Technology in Pasadena, manages Stardust-NExT for the NASA Science Mission Directorate, Washington, D.C. Joe Veverka of Cornell University, Ithaca, N.Y., is the mission's principal investigator. Lockheed Martin Space Systems, Denver, built the spacecraft and manages day-to-day mission operations.

For more information about Stardust-NExT, please visit http://stardustnext.jpl.nasa.gov .

NASA JPL Image: Comet Tempel 1

NASA's Stardust-NExT mission took this image of comet Tempel 1 at 8:38 p.m. PST (11:38 p.m. EST) on Feb 14, 2011, from a distance of approximately 946.05 trillion kilometers (587.85 trillion miles). 

The comet was first visited by NASA's Deep Impact mission in 2005. Stardust-NExT is a low-cost mission that will expand the investigation of comet Tempel 1 initiated by NASA's Deep Impact spacecraft. JPL, a division of the California Institute of Technology in Pasadena, manages Stardust-NExT for the NASA Science Mission Directorate, Washington, D.C. 

Joe Veverka of Cornell University, Ithaca, N.Y., is the mission's principal investigator. Lockheed Martin Space Systems, Denver, built the spacecraft and manages day-to-day mission operations. For more information about Stardust-NExT, please visit http://stardustnext.jpl.nasa.gov

Credit: NASA/JPL-Caltech/Cornell

NASA Jet Propulsion Laboratory California Institute of Technology

NASA EPOXI Mission: Hartley-2 outgassing drives propulsion

This enhanced image, one of the closest taken of comet Hartley 2 by NASA's EPOXI mission, shows jets and where they originate from the surface.

There are jets outgassing from the sunward side, the night side, and along the terminator - the line between the two sides.

The image was taken by EPOXI's Medium-Resolution Instrument on Nov. 4, 2010. The sun is to the right. Credit: NASA/JPL-Caltech/UMD

Analysis of the spectral signatures of the materials coming from the jets shows primarily CO2 gas (carbon dioxide) and particles of dust and ice.

"Previously it was thought that water vapour from water ice was the propulsive force behind jets of material coming off of the body, or nucleus, of comet," said University of Maryland astronomy professor Jessica Sunshine, who is deputy principal investigator for the EPOXI mission.

"We now have unambiguous evidence that solar heating of subsurface frozen carbon dioxide (dry ice), directly to a gas, a process known as sublimation, is powering the many jets of material coming from the comet.

This is a finding that only could have been made by traveling to a comet, because ground based telescopes can't detect CO2 and current space telescopes aren't tuned to look for this gas," Sunshine said.

Sunshine and other members of the EPOXI science team are meeting all this week at the University of Maryland to analyse the very large amount of data from the closest approach, and new data continues to come down at a rate of some 2,000 images a day.

NASA: Flight of the Comet Hartley-2

Click on the picture to see the video clip of the Hartley-2 comet flyby. 

It is comprised of 40 frames taken from the spacecraft's Medium-Resolution Instrument during the encounter. Image credit: NASA/JPL-Caltech/UMD/Brown University
 
› See the movie here

More of the story - Flight of the Comet - NASA Jet Propulsion Laboratory

NASA JPL: Hartley-2 comet fly-by first low res images

Replay the stream and watch the excitement develop

NASA's Jet Propulsion Laboratory invited us to watch live and chat about the Hartley comet flyby and to view the amazing images as they happened.

From the lab to the lecture hall, get information directly from scientists and engineers working on NASA's latest missions.

NASA EPOXI Mission - Deep Impact's Encounter with Comet Tempel 1

This artist's concept shows us the first time Deep Impact encountered a comet - Tempel 1 in July 2005. Deep Impact, now in an extended mission called EPOXI, will fly by its next comet, Hartley 2, on Nov. 4, 2010.

Image Credit: NASA/JPL-Caltech/UMD

Here are five quick facts about the EPOXI mission, scheduled to fly by comet Hartley 2 on Nov. 4, 2010.

1. High Fives - This is the fifth time humans will see a comet close-up, and the Deep Impact spacecraft flew by Earth for its fifth time on Sunday, June 27, 2010.

2. Eco-friendly Spacecraft: Recycle, Reuse, Record - The EPOXI mission is recycling the Deep Impact spacecraft, whose probe intentionally collided with comet Tempel 1 on July 4, 2005, revealing, for the first time, the inner material of a comet. The spacecraft is now approaching a second comet rendezvous, a close encounter with Hartley 2 on Nov. 4. The spacecraft is reusing the same trio of instruments used during Deep Impact: two telescopes with digital imagers to record the encounter, and an infrared spectrometer.

3. Small, Mighty and Square-Dancing in Space - Although comet Hartley 2 is smaller than Tempel 1, the previous comet visited by Deep Impact, it is much more active. In fact, amateur skywatchers may be able to see Hartley 2 in a dark sky with binoculars or a small telescope. Engineers specifically designed the mighty Deep Impact spacecraft to point a camera at Tempel 1 while its antenna was directed at Earth.

This flyby of comet Hartley 2 does not provide the same luxury. It cannot both photograph the comet and talk with mission controllers on Earth. Engineers have instead programmed Deep Impact to dance the do-si-do. The spacecraft will spend the week leading up to closest approach swinging back and forth between imaging the comet and beaming images back to Earth.

4. Storytelling Comets - Comets are an important aspect of studying how the solar system formed and Earth evolved. Comets are leftover building blocks of solar system formation, and are believed to have seeded an early Earth with water and organic compounds. The more we know about these celestial bodies, the more we can learn about Earth and the solar system.

5. What's in a Name? - EPOXI is a hybrid acronym binding two science investigations: the Extrasolar Planet Observation and Characterization (EPOCh) and Deep Impact eXtended Investigation (DIXI). The spacecraft keeps its original name of Deep Impact, while the mission is called EPOXI.

Comet Watchers get ready for C/2009 R1

The C/2009 R1 comet is nearing the Earth and will be visible in the Northern hemisphere with a naked eye in mid-June, NASA said on its website. The comet, discovered in 2009 by well-known British-Australian astronomer and "comet-catcher" Robert H. McNaught, is already visible through powerful binoculars in the morning sky.

NASA said the comet will reach its closest proximity to the Earth by June 15 and could shine just above the horizon in the Perseus constellation. It could be brighter than Venus and visible during the day.

The comet's green plasma head, or coma, is larger than the planet Jupiter, while the long willowy ion tail stretches more than a million kilometers through space.

Russian astronomer Leonid Yelenin from the Keldysh Institute of Applied Mechanics said on Tuesday the comet would be clearly visible in Russia.

"It will be visible in the morning and will present a good object for observation, although its beautiful tail is unlikely to be discernable," Yelenin said.

He said the brightness of the comet could vary as it nears the Sun and could either fade quickly or suddenly increase its magnitude.

"Different models estimate its brightness at magnitude three or even one," he said.

The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, normalized to the value it would have in the absence of the atmosphere.

The brighter the object appears, the lower the value of its magnitude. Very bright objects have negative magnitudes.